Punching apparatus



June 19, 19 45. WALES 2,378,603

PUNCHING APPARATUS Filed May 12, 1945 2 Sheets-Sheet 1 ATTORNEY PatentedJune 19, 11945 UNITED STATES PATENT. OFFICE PUNCHING APPARATUS George F.Wales, Kenmore, N. Y.

Application May 12, 1943, Serial No'. 486,629

26 Claim.

This invention relates to an apparatus for punching holes at specifiedlocations throughout the areas of sheets of material suchas sheet metal,and is particularly adapted for punching the numerous rivet holesrequired in the thin metal panels or sheets which are used in aircraftconstruction to form the outer surfaces of wings, fuselages, and thelike, but the invention may be applied to other uses where relativelylarge numbers of holes are required in panels or sheets of materials.

The main object of my invention is to provide an improved apparatus andmethod for punching holes in sheet materials, which is simple inconstruction, economical to manufacture and use, and efficient in itspurpose and which can be made to operate on work sheets of any desiredsize.

Another object of this invention is to provide punching apparatus whichis constructed to be used on die sets of the kind commonly employed inconnection with presses. Another object. is to provide apparatus of thistype in which the punches, when the ram is in its upper position arespaced at a considerable distance from the dies so that the insertion ofthe work between the punches and dies is facilitated. A further objectof this invention is to provide apparatus of this type in which dieplates and punch plates can be readily supported in such a manner thatthese plates are not subjected to strains'before or during the punchingoperations, to avoid such deflection of the plates as would cause thepunch units to be supported out of axial alinement with the die units.

Further objects and advantages of this invention will appear from thefollowing description and claims.

In the accompanying drawings:

Fig. 1 is the front elevation, partly in section, of a press withpunching apparatus embodying my invention mounted in it and showing theram in an elevated position.

Fig. 2 is a plan view of the lower part thereof, taken on line 22, Fig.1.

Fig. 3 is an enlarged fragmentary view thereof, with the ram in itslowest position and the punch penetrating the work.

Fig. 4 is a fragmentary view of the same punch and punch guide as shownin Fig. 3 in its nonoperative position.

Fig. 5 is a fragmentary elevation, partly in section, of a portion of myapparatus, showing a pilot locator pin cooperating with a prepunchedlocating hole in the workpiece for correctly positioning the workpiecewith reference to the punches and dies.

Fig. 6 is a fragmentary sectional elevation, showing a sleeve used foraligning the punch and die elements when installing the assembled punchplate and its companion die plate to their respective holders? i Fig. 7is a fragmentary sectional elevation of a punching apparatus of modifiedconstruction, the punch units being shown in the positions which theyoccupy when the rain has been moved downwardly through a part of itsstroke.

Fig. 8 is a fragmentary plan view of the die plate and a die unit asseen along line 88, Fig. 7.

Fig. 9 is a fragmentary top plan view of one of the punch units shown inFig. '7.

Fig. 10 is an elevation, on a reduced scale, of still another modifiedform of my invention'.

My improvedpunching apparatus may be used on a press or machine of anysuitable construction, that shown including a stationary bed it havingframe members I! on which. ram i2 is guided to reciprocate toward andaway from the bed. Upon the bed, a bolster plate i3 is mounted asstandard procedure in most stamping plants and upon this bolster ismounted a lower die shoe it. Bolster plate l3 isbolted firmly to bed Itand die shoe i4 is in turn bolted firmly to the bolster plate. To theram of'the press a punch holder or shoe is is firmly attached so that itmoves toward and away from the die shoe it when the ram reciprocates Inorder to assure proper alignment between punch and die implements whichare interchangeably mounted on punch holder I 5 and die shoe i i,conventionalmeans are provided for guiding these two members, includingguide posts l6 which are mounted firmly in die shoe It and companion diebushings I! are mounted in punch holder 85. Thus upon being lowered, theopenings in bushings l'i cooperate with guide posts it to assure properalignment between the punch holder and die shoe.

In stamping plant practice the die shoe it, guide posts it, punch holderi5, and bushings I7, is referred to as a die set. While a die set ispreferably employed to ensure accuracy of movement of the'punchesrelatively to the dies, yet my invention may be used without a die setif a press is available in which the ram moves accurately toward andfrom the bed, or if other-means are provided for ensuring accurate axialmovement of the punches relatively to the dies. Consequently, in theclaims, the bolster plate l3 and the die shoe I 4 of the die set, unlessspecifically mentioned, are considered as a part of the bed of thepress, and the punch holder i5, unless specifically mentioned, isconsidered as part of the ram.

It is the purpose of this invention to place the master die set in thepress as shown in Fig. 1 and allow it to remain in place while the punchand die implements are changed to perform different patterns of holepunching operations on different kinds of work.

In the preferred construction as shown in Fig.

1, I fasten securely to punch holder ll, spacer supports l8 which havetapped holes IQ for the accommodation of screws 20 which are used tohold punch plate 2| firmly attached to said spacer supports. When theworkpieces are large and require large punch plates 2|, additionalspacer supports l8a, which may be in the form of posts, may be providedat intermediate portions of the punch holder I and punch plate 2| toprevent sagging or deflection of the punch plate.

In die shoe I4, I provide tapped holes 22 for the accommodation ofscrews 23 which are used to hold die plate 24 firmly in position on dieshoe l4.

In preparing to punch holes in various sizes and shapes of parts, theblank punch plate 2| is clamped to die plate 24 in such manner thatholes may be formed in both plates in exact relation and alignment withone another, as shown in Figs. 2, 3, and 4 of my Patent No. 2,275,- 706of March 10, 1942, these holes being formed according to the pattern ofholes required in the work. The plates are then separated and preparedin any suitable manner for use in erforating the work. For example, theholes in one or other of the two plates may be enlarged to receive punchor die units. In the construction shown in Figs. 1 to 4, the holes 25formed in die plate 24 may have die elements pressed into them in suchmanner that the lower end 21 will be in contact with the upper face ofthe die shoe l4 when in operation. Each die element 26 is provided witha die opening 28 which is slightly larger in size than its companionpunch and which communicates with a cross passage 29 through which thepunch-out slugs are cleared from the die element. As many of these dieelements 26 as are required are pressed into die plate 24 and the dieopenings 28 may, of course, vary to suit con 'itions. The numeral 30represents the workpiece. Various workpiece locating gages may be used,but in this particular instance, I show locating pins '3| havinglocating pilots 32 which enter into-pre-punched holes 33 in theworkpieces when placed in the apparatus. At least two of these locatingpins are required when anything but circular work is being operatedupon. These locating pins may also be pressed into holes in the dieplate, as shown in Fig. 5. Any other suitable stop gage means forcorrectly positioning the work relatively to the die elements may beemployed.

To punch plate 2| I add punching devices or punch units comprising apunch bit 34, punch body 35, and head 36, said punch bit and body beingguided in a punch sleeve 31 which has a sliding fit in the holes inpunch plate 2|. Punch guide sleeve 31 is provided with a head 38 whichlimits its downward travel and prevents it from dropping out of thepunch plate when in its inoperative position, as shown in Fig. 4.

Interposed between the guide sleeve head or flange 38 and punch head 36,is a stripper spring 39 of any suitable kind which is of sufflcientstrength to withdraw the punch bit 34 from the workpiece after havingpenetrated same.

When the punch and die units have been correctly assembled on the punchand die plates, these plates are then mounted on punch holder I5 and thedie holder or shoe H of the die set. In order to facilitate thisassembly, the punch and die units are preferably aligned by means of analigning sleeve 40 which fits snugly about the die 26 and the punchguide sleeve 31. When two or more such sleeves are used, the punch anddie plates can readily be placed in such positions relatively to eachother that all of the punches will be in axial alignment with theirdies, and the plates are then secured in place by means of the screws 20and 23.

The punch and die plates for each type of work can, consequently, beprepared and have the punch and die units mounted thereon while out ofthe press, and the press is, consequently, idle only while one set ofplates is removed from the die set and another set of plates is securedto the die set. When a job has been completed by punching the requirednumber of workpieces, the punch and die units can be removed from theirplates and used on other plates for another job.

It is an important feature of this invention that the punch units are sosupported on the punch plate 2| that none of the forces required forperforating and stripping are transmitted to or through the punch plate,since any deflection of the punch plate would cause the punches to moveout of axial alignment with the dies, thus either producing defectivework or breaking the punches. By means of the constructionshown, thepunch plate merely supports its own weight and the weight of the punchunits mounted thereon. Consequently, the punches are so mounted on thepunch plate that the upper faces of the heads of the punches are eitherspaced from or just barely touch the lower face of the punch holder l5of the die set, so that the punch units are out of pressure contact withthe punch holder. When so arranged, the stripper springs are not,undercompression and exert no force on the punch plate 2| other than theirown weight. 01 course, if in some situations it were desirable to placesprings 39 under a strong initial compression, longer springs than areshown in the drawings would be used. As plate 2| would be drawn againstthe faces of spacers l8, this result would be accomplished, and it is tobe understood that this arrangement would also be Within the scope ofthis invention.

In the operation of the apparatus described, when the ram I2 of thepress descends, the parts mounted thereon move with the ram withoutrelative motion until the guide sleeves 3i engage the upper face of thework 30. Thereupon farther downward movement of the ram causes the punchunits to remain stationary while the punch plate 2| and punch holder l5descend. As soon as the heads of the punches engage the punch holder 5,the punches again move downwardly, the punch bits penetrating the workand entering the die openings to perforate the work. This movement ofthe punches relatively to the stationary punch guide sleeves compressesthe stripper springs as shown in Fig. 3.

When the ram begins its upward movement, the stripper springs againexpand, thus stripping the punches from the work while urging the guidesleeves 31 downwardly against the work. When the punches are withdrawnfrom the work, the stripper springs preferably withdraw the lower endsof the punches into their guide sleeves to a slight extent, as shown inFig. 4, and the punch units then move by gravity in to the positionshown in Fig. 4.

In order to align the various punching elements with their companion dieelements, I provide sleeves 40 which are used when setting the pairs ofplates into the apparatus before finally tightening the plates in theirmountings. For this down in the hole.

' movement of the guide sleeve.

purpose, the die unit and the punch guide sleeve r re made of the sameoutside diameter so that the aligning sleeve will accuratelyalign-apunch unit with adie unit. If two or more of these aligningsleeves are employed, then all of the punchesand dies of the apparatuswill be in correct alignment,

and then the punch and die plates may be tightly bolted respectively tothe punch holder and die shoe. Any other suitable alignment means may beused, if desired.

In Figs. '1 to 9, I have shown how my improvetion shown, the die is ofsimilar cross sectional shape as the guide sleeve, and consequently,-the non-circular holes in the punch plate andzdie plate may be formedwhile the two plates are the upper end thereof threaded and is providedments may be used in connection'with non-cir cular holes or with aplurality of holes spaced closely together in such a manner that asingle punch unit and die unit may produce more than one hole. In thesefigures, a punch guide sleeve II is provided which is of non-circularshape in cross section, and this guide sleeve is arranged in a hole inthe punch plate which is of similar shape, so that the guide sleeve mayslide up and The guide sleeve is provided with a plurality of aperturesto receive the punches 52 and 83, three such punches being shown in thedrawings. The guide sleeve has a head or flange 54 adapted to rest onthe top surface of the punch plate to limit the downward Each punch mayhave an individual head, but if the punches are closely spaced, thepunches have their upper ends arranged in a common head 56. This may bedone in any suitable-or desired manner, and in the construction shown byway 01' example, the head 58 is provided with threaded holes and theupper ends of the punches are also threaded so that they can be screwedin the holes. The punches terminate short of the upper end of the head56 and set screws are arranged in the upper ends of the threaded holesin the head 56 and preferably engage the upper ends of the punches so asto lock the punches against turning in their heads. This constructionalso has the further advantage that as the punches 52 and 53 becomeshortened by grinding the ends of the same for sharpening the punches,the punches may be screwed into their heads 56 to a lesser extent, sothat the lower ends of the punches can be maintained in the samerelation to the lower ends of the guide sleeve as when the punches werelonger.

when the punches are arranged so closely together that it is notpractical to provide a stripper vided, which extend through the yokeplate GI and the head or flange 54 of the guide sleeve to hold thestripper springs in place. If desired, the screws 62 may be tightened soas to place the stripper springs under initial compression. I

The die 63 for cooperation with the punch unit shown in Fig. '7 may beof any suitable or desired form, and in the construction illustrated,this die is also of elongated cross section, as shown in Fig. 8, and isprovided with die holes or apertures 64 and 65 for the punches. The diemay be provided with inclined passages 66 and 61 which connectrespectively with the die holes 64 and'65 to permit the slugs orpunchings to be discharged from the die. I

The die 63 is pressed into a correspondingly with a head II which isinternally threaded so that it may be screwed on the upper end of themonth. A look nut ll serves to hold the head II from turning relativelyto the punch. The guide sleeve 13 of the punch may be similar inconstruction to the guide sleeves shown in Figs. 1 to 4. It will beunderstood that thispunch. unit is interchangeable with the punch unitsdescribed in connection with Figs. 1 to 4. The multiple punch. unitshownin Fig. "I may, of course, be used in combination with otherpunch units.

It is also possible to punch non-circular holes in connection with myimproved punching apparatus, and when this is done, the punch and dieunits must be held against turning relatively to their punch and dieplates. punching non-circular holes, punch sleeves of non-circularshape, such for example as the punch sleeve 50.- and die units ofnon-circular shape, such as the die unit 83, may be employed, which willbe held against turning relatively to their punch and die plates.

In Fig. 10, I have shown a punching apparatus of slightly modifiedconstruction, in which the punch plate and the punch units supportedthereon may be similar to those described in connection with Figs. 1 to4, but in which the die plate may be of the type disclosed in mycopending application Serial No. 479,749, filed March 19, 1943. In thisconstruction, the die plate to is provided with apertures 8| thereinwhich serve as the dies. This die plate is supported on the die shoe Itof the die set in spaced relation thereto so that the slugs or punching's may drop into the space below the die plate 80. Consequently, theend portions of the die plate may be supported by means of pillars orstandards 83 which may be secured tothe die shoe M in any suitablemanner, for example, by means of angle-shaped clamping members 86engaged by bolts 85 to hold the pillars 83 on the die shoe Hi. If thedie plate 80 is of large size, one or more intermediate supports 86nlilay be provided between the die plate and the die s oe.

' The perforating apparatus described has the advantage that it can beused in connection with die sets in which the upper and lower shoes ofthe die set are guided for accurate movement relatively to each other,so that the apparatus herein disclosed is particularly suitable forcases where" a relatively large opening is desired between the punch-anddie units to facilitate the correct positioning'oi' the work in theapparatus. By the use of a die set, the upper or punch holder member ofwhich is secured directly to the ram of the press, the punch and dieunits may be' R shaped hole in the die plate 88. In the construc-Consequently, for

I guide sleeve, and said sacrifice of accuracy in punching. Since thedie,

plate 24, as shown in Figs. 1 to 9., is supported throughout its lowersurface on the die shoe of the press, no deflection of the die platewill result. The die plate 80 in Fig. can also be held in flat positionby use of the required number of pedestals or supports 83 and $8. Thepunch plate also may be of large'size, since it may be supported notonly at the edge portions thereof, but also intermediate of the edges bymeans of. supports its so that saggin f this plate is reduced to aminimum. It is also of importance that the punch units are so mounted onthe punch plate that none of the forces required for punching the workand stripping the punches from the work pass through the punch plate.This is accomplished by providing punch units which do not extend abovethe punch plate to a greater extent than the space between the punchplate 2| or BI and the punch holder it. Hence the punch plate will atall times be free from any stresses, except those which result from itsown weight and the weight of the guide sleeves. Consequently, bypreventing sagging or deflection of the punch and die plates, theseveral punches will remain vat all times in correct axial alinementwith their dies. 1 I

I claim as my invention: l. Perforating apparatus for use in a presshaving a bed and a ram movable toward and from the bed, including apunch plate secured in spaced relation to said ram and having holestherein arranged in accordance with the pattern of holes required in thework, punch units each including a punch slidably arranged in a punchguide sleeve and having a part arranged to engage said ram for forcingthe punch through the work, and a stripper spring normally holding thepunch within the guide sleeve and arranged in the' space between saidram and said punch plate, said sleeves being slidably fitted in saidholes, and a die for each punch and mounted on said bed, said sleevesengaging the work upon descent of the ram and being slid upwardly tocompress said stripper springs while the punches are forced through thework by said ram.

2. Perforating apparatus for use in a press having a bed and a rammovable toward and from the bed, including a punch plate secured inspaced relation to said ram and having holes therein arranged inaccordance with the pattern of holes required in the work, punch unitseach including a punch, a punch guide sleeve and a stripper spring, saidpunch being slidable in said guide sleeve being slidable in a hole in apunch plate, said punch having a head extending into proximity to saidram and said guide sleeve having a flange on its upper portion, saidstripper spring being arranged between said head and flange, a die foreach punch and from the bed, including a punch each including a punchguide sleeve slidably mounted in a hole in said plate and having aflange at its upper-"end to limit downward movement of said punch guidesleeve relatively to said punch plate, a punch slidable in said guidesleeve and having a head on the upper end thereof spaced above saidflange, and a stripper spring arranged between said head and saidflange, means for securing said punch plate to said punch holder of thedie set in such spaced relation thereto that such springs will besubstantially free from compression, a die plate secured to said dieholder of said die set with die holes arranged in axial alignment withsaid punches, said sleeves upon downward movement of said punch plateand the punch holder of said die set being slid upwardly in their holesupon engagement with the work to compress said stripper springs whilesaid punches are forced through the work, the pressure of said springsupon upward movement of said punch plate and punch holder stripping thework from said punches.

4. Perforating apparatus for use in a press having a bed and a rammovable toward and plate secured in spaced relation to said ram andhaving holes therein arranged in accordance with the pattern of holesrequired in the work, punch units each including a punch slidablyarranged in a punch guide sleeve and having a part arranged to engagesaid ram for forcing the punch through the work, and a stripper springnormally holding the punch within the guide sleeve and arranged in thespace between said ram and said punch plate, said sleeves being slidablyfitted in said holes, a die plate having holes therein and secured tosaid bed and having a plurality of die units pressed into said holes andextending upwardly above mounted on said bed, saidsleeves, upon descentof said ram, engaging the work and being moved by the work upwardly tocompress said springs while said punches are moved by said ram throughthe work.

3. Perforating apparatus for use in a press having a bed and a rammovable toward and from the bed, and having a die set mounted in saidpress with a die shoe secured to said bed and a punch holder secured tosaid ram, a punch plate having holes formed therein according to thepattern of holes required in the work, punch units arranged in saidholes in said punch plate and said plate and having die openings inaxial alignment with the punches, said sleeves upon descent of said ramengaging the work resting on said dies and being slid upwardly bycontact with the work to compress said stripper springs while thepunches are forced through the work by said ram.

5. Perforating aparat'us for use in a press having a bed and a rammovable toward'and from the bed, including a punch plate secured inspaced relation to said ram and having holes therein arranged inaccordance with the pattern of holes required in the work, punch unitseach including a punch slidably arranged in a punch guide sleeve andhaving a part arranged to engage said ram for forcing the punch throughthe work, and a stripper spring normally holding the punch within theguide sleeve and arranged in the space between said ram and said punchplate, said sleeves being slida-bly fitted in said holes, and a dieplate 'mounted in spaced relation to said bed and having die holestherein each of which is in axial alignment with a punch on said punchplate, said sleeves upon descent of the ram engaging the work and beingslid upwardly to compress said stripper springs while the punches areforced through the work by the ram.

6. A punch plate for use on the ram of a press, said punch plate havinga plurality of apertures formed therein in accordance with the patternof holes required in the work, a punch guide sleeve slidably mounted ineach aperture and having a flange at the upper end to limit the downwardmovement of the guide sleeve in its hole, a'punch slidably arranged insaid guide sleeve and extending above the same, a head on said punch,and a stripper spring arranged to act on said head and said flange forholding the work penetrating end of the punch within said sleeve.

7. The combination of a punch plate for use on the ram of a press, saidpunch plate having a plurality of apertures formed therein in accordancewith the pattern of holes required in the work, a punch guide sleeveslidably mounted in each aperture and having a flange at the upper endto limit the downward movement of the guide sleeve in its hole, a punchslidably arranged in said guide sleeve and extending above the same, ahead on said punch, a stripper spring arranged to act on said head andsaid flange for holding the work penetrating end of the punch withinsaid sleeve, and means for mounting said punch plate in spaced relationto the ram 01 the press with the heads of the punches clearing the ramthe press to prevent compression ofsaid spri s and deflection of saidpunch plate.

8. The combination of a die plate for use on the bed of a press, saiddie plate having a plurality of apertures formed therein in accordancewith the pattern of holes required in the work, die units having theirlower portions formed to be pressed into said holes with their lowerends flush with the bottom of said die plate, said die units havingapertures in the upper ends thereof and discharge openings connectingwith said die apertures and terminating in the sides of said units abovesaid plate for discharging punchings on said plate, and means forsecuring said die plate on the bed of a press.

9. A perforating apparatus, including a die set having a die shoe and apunch holder guided for accurate movement toward and from the die. shoe,a punch plate having apertures therein located according to the patternof holes desired in the work, means for securing said punch plate inspaced r lation to said punch holder, and a plurality of punch unitseach including a guide sleeve slidable in an aperture in the punchplate, a punch slidable in said sleeve and extending above said sleeve,and a stripper spring acting on the up er portion of the punch and theguide sleeve, said punch units extending above said punch plate adistance not greater than the space between said punch plate and saidpunch holder to prevent said units from exerting pressure on said punchplate when the,same is secured to said Punch holder.

10. The combination with a die set having a die shoe and a punch holderguided for accurate movement toward and from the die shoe, of a punchplate having a plurality of punch and stripper units including punches,punch guide sleevesand stripper springs i-loatingly mounted on saidpunch plate, and means for supporting said plate in spaced relation tothe punch holder of the die set with the punch and stripper units out ofpressure contact with said punch holder, to p rmit the punches of saidunits to move into engagement with the punch holder when engaging thework.

11.'The combination with a die set having a die shoe and a punch holderguided for accurate movement toward and from the di shoe, of a punchplate having a plurality of punch and stripper units including a punchguide sleeve slidable vertically relatively to said plate, punchesslidable in said sleeves, and stripper springs yieldingly holding theWork penetrating ends of said punches in said sleeves, and means forsupporting said plate in spaced relation to the punch holder oi the dieset with the punch and stripper units out of pressure contact with saidpunch holder, to permit the punches or said units to move intoengagement with the punch holder whenengaging the work.

12. Perforating apparatus for use in a press said sleeves slide in saidholes.

, 13. A perforating apparatus for use on a press including a, punchplate and a die plate, said plates having aligned non-circular holestherein, a guide sleeve of non-circular cross section slidably arrangedin the hole in said punch plate and held against turning relatively tosaid punch plate, a punch slidable in said sleeve and having the upperend thereof extending above said sleeve, a stripper spring acting onsaid sleeve and said punch for urging the work engaging end of saidpunch into said sleeve, and a die oi noncircular cross section arrangedin said hole in said die plate and having a punch receiving openingthereinarranged to receive said punch when said plates are arranged inoperative relation to each other.

14. A perforating apparatus for use on a press including a punch plateand a die plate, said plates having aligned non-circular holes therein,a guide sleeve of non-circularcross sectionslidably arranged in the holein said punch plat and held against turning relatively to said punchplate, a plurality of punches slidably arranged in said sleeve, strippersprings acting on said punches and sleeves and urging the workpenetrating ends of said punches into said sleeves, and a die ofnon-circular cross section arranged in said hole in said die plate andhaving a plurality of apertures therein to receive said ends of saidpunches.

15. A perforating apparatus for use on a press including a punch plateand a die plate, said plates having aligned non-circular holes therein,a guide sleeve .of non-circular cross section slidably arranged in thehole in said punch plate and held against turning relatively to saidpunch plate and having a plurality of holes extending lengthwise throughthe same, punches slidably arranged in said holes, a head to which theupper ends of said punches are secured, resilient stripping means forthe punches, which act on said head, and said sleeve to draw the workpenetrating ends of the punches into said sleeve, and a die ofnon-circular cross section arranged in said hole in said die plate andhaving a plurality of apertures therein to receive said work penetratingends of said punches.

16. A perforating apparatus for use on a press including a punch plateand a die plate, said plates having aligned non-circular holes therein,a guide sleeve of non-circular cross section slidably arranged in thehole in said punch plate and held against turning relatively to saidpunch plate and having a plurality of holes extending lengthwise throughthe same, punches slidably arranged in said holes, a head to which theupper ends of said punches are secured, a yok engaging said head, andstripper sp ings engaging said yoke and said sleeve to draw the workpenetrating ends of said punches into said sleeve, and die means withwhich said punches cooperate to per-. forate the work.

1'7. A punch plate for use on the ram 01 a press, said punch platemounted in spaced relation to said ram and having a hole therein, a

guide sleeve slidably arranged in said hole. a

punch slidably arranged in said sleeve and having a part extending abovesaid sleeve for engagement with said ram and having a screw-threadedupper end, a head having a threaded hole and engaging saidscrew-threaded end of said punch, and a screw plug in the upper end 01said screwthreaded hole and engaging said punch for locking said punchagainst turning relatively to its head.

18. A punch platefor use on the ram of a press, said punch plate mountedin spaced relation to said ram and having a hole therein, a

guide sleeve slidably arranged in said hole, a punch slidably arrangedin said sleeve and having a part extending above said sleeve forengagement with said ram and having a screwthreaded upper end, a headhaving a threaded hole and engaging said screw-threaded end of saidpunch, and a lock nut on said punch and engaging said head to hold saidpunch against turning relatively to said head.

19. The combination with a die set having a die shoe and a punch holderguided for accurate movement toward and from the die shoe, of a punchplate having a plurality of punch and stripper units including punches,punch guide sleeves and stripper springs floatingly mounted on saidpunch plate, means for supporting said plate in spaced relation to thepunch'holder of the die set with the punch and stripper units out'ofpressure contacts with said punch holder, to permit the punches of saidunits to move into engage- ,ment with the punch holder when engagin thework, and a die plate having die apertures for cooperation with saidpunches and mounted in spaced relation to said die shoe.

20. The combination with a die set having a die shoe and a punch holderguided for accurate movement toward and from the die shoe, or a punchplate having a plurality of punch and stripper units includingpunches,punch guide sleeves and stripper springs floatingly mounted on saidpunch plate, means for supporting said plate in spaced relation to thepunch holder of the die set with the punch and stripper units out ofpressure contact with said punch holder, to permit the punches of saidunits .to move into engagement with the punch holder when engaging thework, a die plate having die apertures for cooperation with saidpunches, and a plurality of supporting members secured to said die shoeand said die plate for mounting said die plate in spaced relation tosaid die shoe.

21. The combination with a die set having a die shoe and a punch holderguided for accurate movement toward and from said die shoe, of a punchplate having a plurality of punch units mounted thereon including guidesleeves extending below the lower face thereof, a die plate having aplurality of die units mounted thereon and extending above said dieplate, and a plurality of aligning sleeves with which some of the guidesleeves and their corresponding die units may telescope to hold saidplate in positions in which each of said punch units is in axialalignment .punch plate having a plurality of punch units mounted thereonincluding guide sleeves extending below the lower face thereof, a dieplate having a plurality of die units mounted thereon and havingcylindrical outer surfaces of the same diameter as said sleeves andextending above said die plate, and a plurality of cylindrical aligningsleeves into which said guide sleeves and die units may telescope tohold said plates in positions in which each of said punch units is inaxial alignment with its die unit, while said plates are secured to saiddie set.

23. The combination of a die plate for use on the bed-of a press, saiddie plate having a plurality of dies arranged thereon in accordance withthe pattern of holes required in the work, pilot means on said dieplate, including pins formed to enter into preformed holes in the work,for locating the Work in correct relation to the dies of said die plate,and a punch plate having punches mounted thereon arranged forcooperation with said dies said pilot means being positioned within thearea under said punch plate.

24. The combination of a die plate for use on the bed of a press, saiddie plate having a plurality of dies arranged thereon in accordance withthe pattern of holes required in the work, die units having their lowerportions formed to be pressed into said holes of said die plate, andlocating units having shank portions formed to be pressed into some ofsaid holes and having locating pins at their upper ends formed to enterinto preformed holes in the work, and means for securing said die plateon the bed of the press said locating units being positioned within thearea under a punch plate which carries die cooperating punches.

25. The combination of a die plate for use on the bed'of a press, saidplate having a plurality of apertures formed therein in accordance withthe pattern of holes required in the work, die units of substantiallyuniform cross section throughout their length having their lowerportions formed to 'be pressed. into said holes of said die plate withtheir lower ends flush with the bottom of said die plate, said die unitshaving die apertures formed axially in the upper ends of said die unitsand having slug discharge apertures in which said die aperturesterminate, said discharge apertures terminating in the sides of saidunits above said plate, and means for securing said die plate to the bedof the press.

26. The combination of a die plate for use on the bed of a press, saiddie plate having a plurality of apertures formed therein in accordancewith the pattern of holes required in the work, die units having theirlower portions formed to be pressed into said holes with their lowerends flush with the bottom end of said die plate and their upperportions being provided with a lateral slugclearing aperture foremitting slugs above said die plate, and means for securing said dieplate on the bed of the press.

GEORGE F. WALES.

